Analyzing tool

ABSTRACT

The present invention relates to an analytical tool (Y) including a liquid introduction port ( 61 ), one or a plurality of flow paths ( 51 ) for moving a sample liquid introduced through the liquid introduction port ( 61 ), and a separation film ( 8 ) for filtering the sample liquid supplied to the liquid introduction port ( 61 ) and then introducing the sample liquid to one or plurality of flow paths ( 51 ). The analytical tool (Y) is structured to move the sample liquid through the separation film ( 8 ) in the thickness direction of the separation film ( 8 ) for filtration. The flow path ( 51 ) is structured to move the sample liquid by capillary action.

TECHNICAL FIELD

The present invention relates to an analytical tool used for analyzing aparticular component contained in a sample liquid (such as blood orurine, for example).

BACKGROUND ART

In an analysis method, reaction liquid obtained upon reaction of asample and a reagent is analyzed by an optical technique, for example.In such a method for analyzing a sample, use is made of an analyticaltool for providing a reaction field. For example, there exist analyticaltools which are designed to remove solid components in the sample liquidbefore the sample liquid is supplied to reagent portions. Examples ofsuch analytical tools include one shown in FIGS. 13 and 14 and one shownin FIGS. 15 and 16 of the present application (See JP-A 2002-508698A andJP-A 8-114539, for example).

The analytical tool 9A shown in FIGS. 13 and 14 includes a substrate 90,a cover 91, and a filter 92 interposed therebetween. The substrate 90 isformed with a space 90 a in which the filter 92 is fitted. The cover 91is formed with a liquid introduction port 92 a located above the filter92. The filter space 90 a is connected to a discharge region 90 b. Inthe analytical tool 9A, liquid is introduced through the liquidintroduction port 92 a to the filter 92 for removal of solid componentsand then guided to the discharge region 90 b.

The analytical tool 9B shown in FIGS. 15 and 16 includes a samplereceiving port 93, a first sample treatment chamber 94 for removing asubstance causing measurement error, a first measurement chamber 95 formeasuring a pre-reaction value, a second sample treatment chamber 96including a reagent portion for reaction with a target substance, asecond measurement chamber 97 for measuring optical characteristics of areaction product of the target substance and the reagent, a filter 98provided in the first sample treatment chamber 94 and directly below thesample receiving port 93, and a pump connection port 99. In theanalytical tool 9B, a sample liquid is introduced through the sampleliquid receiving port 93 to the filter 98 for removal of solidcomponents and then guided to the first sample treatment chamber 94.With a pump connected to the pump connection port 99 of the analyticaltool 9B, the sample liquid is sucked by the motive power of the pump formovement through the chambers 94-97.

In the analytical tools 9A and 9B, the removal of solid components atthe filters 92, 98 is performed mainly when the sample liquid moves inthe plane direction of the filters 92, 98. Therefore, in the analyticaltools 9A and 9B, a large filtration length can be attained, so thatefficient removal of solid components is expected. On the other hand,however, there is a fear that the removal of solid components takes longtime and the measurement time becomes long due to the large filtrationlength and a long retention time of the sample liquid in the filters 92,98. Such a fear is serious in an analytical tool designed to move asample liquid by utilizing capillary action. Moreover, in such ananalytical tool as a microdevice which has a flow path of a smallsectional area, the movement of a sample liquid through the small flowpath by capillary action becomes difficult when the sample liquid has ahigh viscosity. In such a case again, the above fear is serious.

When a sample liquid is moved by utilizing motive power of a pump as isin the analytical tool 9B, the sample liquid can be moved relativelyeasily, so that the above fear relating to the measurement time is notserious. However, since the apparatus for performing analysis by usingthe analytical tool 9B need be provided with a pump, the cost for theapparatus increases correspondingly. Moreover, the use of the pumpincreases the cost required for a single time of measurement.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide an analytical toolwhich is capable of removing solid components contained in a sampleliquid without increasing the measurement time and which is advantageousin terms of cost.

According to the present invention, there is provided an analytical toolcomprising a liquid introduction port, one or a plurality of flow pathsfor moving a sample liquid introduced through the liquid introductionport, and a separation film for filtering the sample liquid supplied tothe liquid introduction port and then introducing the sample liquid tothe one or a plurality of flow paths. The sample liquid is caused tomove through the separation film in the thickness direction of theseparation film for filtration.

In the analytical tool, the sample liquid is moved in the thicknessdirection of the separation film for removal of solid componentscontained in the sample liquid. Therefore, as compared with thestructure in which the sample liquid is moved in the plane direction ofthe separation film, the retention time of the sample liquid in theseparation film becomes shorter. As a result, the sample liquid does notreceive so high resistance in the separation film and can pass throughthe separation film in a relatively short period of time. Thus, the timenecessary for the removal of solid components and the measurement timecan be shortened. Since the resistance in the movement of the sampleliquid is low, the sample liquid can be moved by capillary action.Therefore, the sample liquid need not be moved by utilizing the motivepower of a pump, so that the apparatus for performing measurement byusing the analytical tool can be manufactured at a relatively low cost.Moreover, since the motive power of a pump need not be utilized, themeasurement cost can be reduced correspondingly.

Since the movement resistance in the separation film can be reduced, theanalytical tool can be structured as a microdevice which utilizescapillary action in a small flow path. In this case, one or a pluralityof flow paths may have a principal, rectangular cross section which hasa width of 10˜500 μm and a depth of 5˜500 μm and which satisfiesdepth/width 0.5. The “principal cross section” herein indicates avertical section extending perpendicularly to the travel direction ofthe sample liquid, and indicates the vertical section of a portion whichis mainly utilized for traveling the sample liquid when the sectionalconfiguration is not uniform.

Preferably, to promote the movement of the sample liquid through theflow path, one or plurality of flow paths may have ahydrophilically-treated inner surface. The hydrophilization may be soperformed that the contact angle of pure water at the inner surfacebecomes 0˜80 degrees, and preferably 0˜60 degrees.

As the sample liquid, a biochemical sample such as urine or blood may beused, and typically, blood may be used.

For example, the separation film is positioned higher than one orplurality of flow paths. With such an arrangement, the sample liquid canbe moved in the thickness direction of the separation film so that solidcomponents can be removed at the separation film. For example, theanalytical tool may further comprise a liquid receiving portion forretaining the sample liquid passed through the separation film, and theliquid receiving portion communicates with the liquid introduction portand one or plurality of flow paths. Preferably, in this case, theseparation film is spaced from the bottom surface of the liquidreceiving portion.

For example, the analytical tool of the present invention may comprise asubstrate in which the liquid receiving portion is formed, a cover inwhich the liquid introduction port is formed, and an adhesive layerinterposed between the substrate and the cover and including athrough-hole for fitting the separation film.

When the analytical tool includes a plurality of flow paths, it ispreferable that the flow paths extend radially from the liquid receivingportion.

The separation film may be selected depending on the size of a solidcomponent to be removed, and for example, a porous material may be used.Examples of porous material which is usable as the separation filminclude paper, foam (expanded material), a woven material, a non-wovenmaterial, a knitted material, a membrane filter, a glass filter, or agel material. When the sample liquid is blood and blood cells in theblood are to be separated at the separation film, it is preferable touse, as the separation film, a material whose minimum pore diameter(pore size) is 0.1˜3.0 μm.

For example, the analytical tool may comprise reagent portions forreaction with the sample liquid, and a plurality of flow paths formoving the sample liquid. In this case, the reagent portions provided inat least two of the flow paths are different from each other in reagentincluded therein. In this case, the tool is adapted to measure aplurality of items from a single kind of sample liquid. Preferably, thereagent portions of the at least two flow paths are arranged on a commoncircle.

Preferably, each of the flow paths is structured to temporarily retainthe sample liquid upstream from the reagent portion before the sampleliquid is introduced to the reagent portion. Specifically, theanalytical tool further comprises a branching flow path branched from achannel set in the flow path. The sample liquid is temporarily retainedat the channel in the flow path by bringing the branching flow path intocommunication with the outside through a portion other than the liquidintroduction port, and the sample liquid is caused to move through theflow path beyond the channel by bringing the flow path intocommunication with the outside through a portion other than the liquidintroduction port. Preferably, the flow path is connected to a gasdischarge port for discharging gas from the flow path, and the sampleliquid is caused to move beyond the channel by opening the gas dischargeport.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing the structure of an example ofanalytical apparatus and analytical tool according to the presentinvention.

FIG. 2 is a sectional view taken along lines II-II in FIG. 1.

FIG. 3 is an entire perspective view of the microdevice shown in FIG. 1.

FIG. 4 is an exploded perspective view of the microdevice shown in FIG.3.

FIG. 5A is a sectional view taken along lines Va-Va in FIG. 3.

FIG. 5B is a sectional view taken along lines Vb-Vb in FIG. 3.

FIG. 6 is a plan view showing a substrate of the microdevice.

FIG. 7 is a bottom view showing a cover of the microdevice.

FIG. 8 is a sectional view showing the operation for opening first gasdischarge ports.

FIG. 9 is a sectional view showing the operation for opening a secondgas discharge port.

FIG. 10 is a schematic view showing the movement of a sample liquidthrough flow paths.

FIG. 11 is an exploded perspective view showing another example ofmicrodevice according to the present invention.

FIG. 12 is a sectional view of the microdevice shown in FIG. 11.

FIG. 13 is a plan view showing a principal portion of a prior artanalytical tool.

FIG. 14 is a sectional view taken along lines XVI-XVI in FIG. 13.

FIG. 15 is an exploded perspective view showing another example of priorart analytical tool.

FIG. 16 is a sectional view showing a principal portion of theanalytical tool shown in FIG. 15.

BEST MODE FOR CARRYING OUT THE INVENTION

FIGS. 1 and 2 show an analytical apparatus X to which a microdevice Y asan analytical tool is mounted for analyzing a sample liquid. Theapparatus includes a mount portion 1 to which the microdevice Y is to bemounted, a light source 2, a light receiving portion 3 and an openingmechanism 4.

As better shown in FIGS. 3 through 5, the microdevice Y, which serves toprovide a reaction field, includes a substrate 5, a cover 6, an adhesivelayer 7 and a separation film 8.

The substrate 5 comprises a transparent circular disk having acircumferential edge which is stepped downwardly. As shown in FIGS. 5Aand 6, the substrate 5 includes a liquid receiving portion 50 formed atthe center thereof, a plurality of flow paths 51 communicating with theliquid receiving portion 50 and extending radially from the liquidreceiving portion 50 toward the circumferential edge of the substrate 4,a plurality of recesses 52 and a plurality of branching flow paths 53.

The liquid receiving portion 50 serves to retain a sample liquidsupplied to the microdevice Y for introduction to each of the flow paths51. The liquid receiving portion 50 comprises a circular recess formedon an upper surface 5A of the substrate 5.

Each of the flow paths 51 serves to move the sample liquid and is formedon the upper surface 5A of the substrate 5 so as to communicate with theliquid receiving portion 50. As shown in FIG. 5A, each flow path 51includes a channel 51A and a reaction portion 51B. The flow path 51 hasa generally uniform rectangular cross section except for the reactionportion 51B. For example, the width and depth of the rectangular crosssection of the flow path 51 are set to 10˜500 μm and 5˜500 μm,respectively, and set so that the depth/width ratio is no smaller than0.5.

As shown in FIGS. 4 and 6, from the channel 51A extends the branchingflow path 53 communicating with the flow path 51. The branching flowpath 53 is provided as close to the reaction portion 51B as possible sothat the distance between the branching flow path 53 and the reactionportion 51B becomes as small as possible. The branching flow path 53 hasa generally uniform rectangular cross section of a dimension similar tothe rectangular cross section of the flow path.

Each of the reaction portions 51B has a sectional area which is largerthan that of the principal cross section of the flow path 51. Thereaction portions 51B are arranged on a common circle. As shown in FIG.5A, each of the reaction portions 51B is provided with a reagent portion54. However, the reagent portion 54 need not necessarily be provided atevery flow path 51. For example, a reagent portion may not be providedwith respect to a flow path that is used for correcting the influence ofthe color of a sample liquid.

The reagent portion 54 comprises a solid which dissolves when a sampleliquid is supplied thereto and exhibits a color upon reacting with aparticular component contained in the sample liquid. In this embodiment,a plurality of kinds of reagent portions 54 which differ from each otherin components or composition are prepared so that a plurality of itemscan be measured in the microdevice Y.

Each of the recesses 52 serves to emit a light toward the lower surface5B side of the substrate 5 when the reaction portion 51B is irradiatedwith light from the upper surface 5A side of the substrate 5 and thelight is transmitted to the recess, as will be described later (SeeFIGS. 1 and 2). The recess 52 is provided at the lower surface 5B of thesubstrate 5 at a location corresponding to the reaction portion 51B.Therefore, as shown in FIG. 6, the recesses 52 are arranged on the samecircle and adjacent to the circumferential edge of the substrate 5.

For example, the substrate 5 is made by molding a transparent resinmaterial such as acrylic resin such as polymethyl methacrylate (PMMA),or polystyrene (PS), polycarbonate (PC) or polyethylene terephthalate(PET). The liquid receiving portion 50, the flow paths 51, the recesses52 and the branching flow paths 53 can be made at the same time in theresin-molding process by appropriately designing the configuration ofthe mold.

Preferably, the inner surfaces of the liquid receiving portion 50, theflow paths 51, the recesses 52 and the branching flow paths 53 arehydrophilically treated. Although various known techniques forhydrophilization can be employed, it is preferable that hydrophilizationis performed by bringing a mixed gas containing fluorine gas and oxygengas into contact with each inner surface and then bringing water orwater vapor into contact with the inner surface. Unlike a prior arthydrophilization technique such as ultraviolet irradiation, this methodis capable of hydrophilically treating a standing surface (side surfaceof a flow path, for example) as well, because this method utilizes gasand water for hydrophilization. The hydrophilization with respect toeach inner surface is so performed that the contact angle of pure waterat the inner surface becomes 0˜80 degrees, and preferably 0˜60 degrees.

The cover 6 is in the form of a circular disk having a downwardlyprojecting circumferential edge. The projection 60 of the cover 6 servesto engage the stepped, smaller-thickness portion of the substrate 5. Asshown in FIGS. 5 and 7, the cover 6 includes a sample introduction port61, a plurality of first gas discharge ports 62, a plurality of recesses63, a common flow path 64 and a second gas discharge port 65.

The sample introduction port 61, which is used for introducing a sampleliquid, comprises a through-hole. As better shown in FIG. 5, the sampleintroduction port 61 is provided at the center of the cover 6 anddirectly above the liquid receiving portion 50 of the substrate 5.

Each of the first gas discharge ports 62, which are used for discharginggas from the flow paths 51, comprises a through-hole. As better shown inFIG. 5B, the first gas discharge ports 62 are provided directly abovethe branching flow paths 53 of the substrate 5, respectively. As aresult, as shown in FIGS. 4 and 7, the first gas discharge ports 62 arearranged on a common circle. As better shown in FIG. 5B, the upperopening of each of the first gas discharge ports 62 is closed by asealing member 62 a. The sealing member 62 a may be made of metal suchas aluminum or resin. The sealing member 62 a is fixed to the substrate5 by the use of an adhesive or by fusing, for example.

The recesses 63 are utilized for irradiating the reaction portions 51Bwith light from the upper surface 6A side of the cover 6, as will bedescribed later (See FIGS. 1 and 2). As shown in FIG. 5A, each of therecesses 63 is provided at the upper surface 6A of the cover 6 anddirectly above the reaction portion 51B. As a result, as shown in FIGS.4 and 7, the recesses 63 are arranged on a common circle and adjacent tothe circumferential edge of the cover 6.

The common flow path 64 serves to guide gas to the second gas dischargeport 65 in discharging gas in the fluid paths 51 to the outside. Asshown in FIGS. 5 and 7, the common flow path 64 comprises an annularrecess provided at a peripheral portion of the lower surface 6B of thecover 6. As shown in FIGS. 5A and 6, the common flow path 64communicates with the flow paths 51 of the substrate 5.

As shown in FIGS. 5A and 7, the second gas discharge port 65 comprises athrough-hole communicating with the common flow path 64. The upperopening of the second gas discharge port 65 is closed by a sealingmember 65 a. As the sealing member 65 a, use may be made of one that issimilar to the sealing member 62 a.

Similarly to the substrate 5, the cover 6 may be made by resin-moldingusing a transparent resin material. The sample introduction port 61, thefirst gas discharge ports 62, the recesses 63, the common flow path 64and the second gas discharge port 65 can be made at the same time in theresin-molding process. It is preferable that the cover 6 as well ishydrophilically treated at least at the portion facing the flow paths 51of the substrate 5. The hydrophilization can be performed by the sametechnique as that for the substrate 5.

As better shown in FIG. 5, the adhesive layer 7 serves to bond the cover6 to the substrate 5. As shown in FIGS. 4 and 5, the adhesive layer 7 isprovided by interposing an adhesive sheet, which is formed with athrough-hole 70 at the center thereof, between the substrate 5 and thecover 6. The through-hole 70 of the adhesive layer 7 has a diameterwhich is larger than those of the liquid receiving portion 50 of thesubstrate 5 and the sample introduction port 61 of the cover 6. Theadhesive sheet may be made by forming adhesive layers at oppositesurfaces of a base material.

The separation film 8 serves to separate solid components contained in asample liquid such as blood cells in blood. As shown in FIG. 5, theseparation film 5 has a diameter corresponding to the diameter of thethrough-hole 70 of the adhesive layer 7 and is fitted into thethrough-hole 70 of the adhesive layer 7 to intervene between the liquidreceiving portion 50 of the substrate 5 and the sample introduction port61 of the cover 6. Since the liquid receiving portion 50 comprises arecess, the separation film 8 is spaced from the bottom surface of theliquid receiving portion 50. Since the diameter of the separation film 8corresponds to the diameter of the through-hole 70 which is larger thanthat of the liquid receiving portion 50, each of the flow paths 51 iscovered by the separation film 8 at a portion which is close to theliquid receiving portion 50. By such an arrangement of the separationfilm 8, the sample liquid introduced through the sample introductionport 61 passes through the separation film 8 in the thickness directionand then reaches the liquid receiving portion 50.

As the separation film 8, a porous material may be used, for example.Examples of porous material used as the separation film 8 includespaper, foam (expanded material), an woven material, a non-wovenmaterial, a knitted material, a membrane filter, a glass filter, or agel material. When the sample liquid is blood and blood cells in theblood are to be separated in the separation film 8, it is preferable touse, as the separation film 8, a material whose minimum pore diameter(pore size) is 0.1˜3.0 μm.

The mount portion 1 shown in FIGS. 1 and 2 includes a recess 10 forholding the microdevice Y. In the mount portion 1 is defined a lighttransmitting region 11. The light transmitting region 11 is provided ata location which corresponds to the reaction portion 51B when themicrodevice Y is mounted to the recess 10. The light transmittingportion 11 is provided by forming the relevant region of the mountportion 1 by using a transparent material such as transparent resin.Alternatively, the mount portion 1 may be entirely made of a transparentmaterial. The mount portion 1 is supported by a rotation shaft 12 sothat the mount portion 1 rotates in accordance with the rotation of therotation shaft 12. The rotation shaft 12 is connected to anon-illustrated driving mechanism and is controlled to rotate by apredetermined angle corresponding to the arrangement pitch of thereaction portions 51B of the microdevice Y.

The light source 2 serves to irradiate the reaction portions 51B of themicrodevice Y with light and is fixed at a position for facing therecesses 63 of the cover 6. The light source 2 may comprise a mercurylamp or a white LED, for example. Though not illustrated, when such alight source is used, the light from the light source 2 is caused topass through a filter before reaching the reaction portions 51B. Byusing such a filter, it is possible to select a light of an appropriatewavelength in accordance with the light absorption characteristics ofthe substance as an object to be analyzed contained in the reactionliquid.

The light receiving portion 3 serves to receive light passed through thereaction portion 51B and is fixed at a position for facing the recesses52 of the substrate 5. The amount of light received by the lightreceiving portion 3 is used as the base for the analysis of the sampleliquid (for the concentration computation, for example). The lightreceiving portion 3 may comprise a photodiode, for example.

The opening mechanism 4 includes a first hole-making member 41 formaking a hole in the seal portion 62 a, and a second hole-making member42 for making a hole in the seal portion 65 a. The hole-making members41 and 42 are reciprocally movable up and down by the operation of anon-illustrated actuator.

The first hole-making member 41 includes a substrate 41 a in the form ofa circular disk, and a plurality of needles 41 b projecting downwardfrom the lower surface of the substrate. As shown in FIG. 8, each of theneedles 41 b has a diameter which is smaller than that of the first gasdischarge ports 62 of the cover 6. The needles 41 b are arranged on acommon circle and at a pitch corresponding to the pitch of the first gasdischarge ports 62. Therefore, when the first hole-making member 41 ismoved downward with the needles 41 b positioned to face the first gasdischarge ports 62, respectively, holes can be made simultaneously withrespect to the plurality of seal portions 62 a. By this operation, eachof the first gas discharge ports 62 opens, whereby the interior of eachflow path 51 is brought into communication with the outside through thebranching flow path 53 and the first gas discharge port 62.

As shown in FIGS. 1 and 9, the second hole-making member 42 includes aneedle 42 a. The needle 42 a has a diameter which is smaller than thatof the second gas discharge port 65 of the cover 6. Therefore, when thesecond hole-making member 42 is moved downward with the needle 42 a ofthe second hole-making member 42 positioned to face the second gasdischarge port 65 of the cover 6, a hole is made in the seal portion 65a. By this operation, the second gas discharge port 65 opens, wherebythe interior of each flow path 51 is brought into communication with theoutside through the common flow path 64 and the second gas dischargeport 65.

The method for opening the first and the second gas discharge ports 62,65 is not limited to those described above. For example, the first andthe second gas discharge ports 62, 65 may be opened by melting ordeforming the sealing members 62 a, 65 a by applying energy to thesealing members 62 a, 65 a. The energy application may be performed byusing a light source such as a laser, an ultrasonic generator or aheating element, for example. Alternatively, the gas discharge ports 62,65 may be opened by peeling off the sealing members 62 a, 65 a.

For analyzing a sample liquid, the sample liquid S is supplied to themicrodevice Y through the sample introduction port 61. The supply of thesample liquid S may be performed after the microdevice Y is mounted tothe analytical apparatus X. However, it is preferable that themicrodevice Y is mounted to the analytical apparatus X after the sampleliquid S is supplied to the microdevice Y.

As will be understood from FIG. 5, when the sample liquid S is suppliedto the microdevice Y, the sample liquid S passes through the separationfilm 8 in the thickness direction of the film to reach the liquidreceiving portion 50. At this time, solid components are removed fromthe sample liquid S. For example, when blood is used as the sampleliquid, blood cells are removed from the blood. Since the first and thesecond gas discharge ports 62, 65 are closed in supplying the sampleliquid S, the sample liquid S is retained in the liquid receivingportion 50 and does not flow into the flow paths 51, as schematicallyshown in FIG. 10A.

In this embodiment, solid components are removed by moving the sampleliquid in the thickness direction of the separation film 8. Therefore,as compared with the structure in which solid components are removed bymoving the sample liquid in the plane direction of the separation film8, the retention time of the sample liquid in the separation film 8becomes shorter. Therefore, the time necessary for removing solidcomponents becomes shorter.

To introduce the sample liquid S to the flow paths 51, holes are madesimultaneously with respect to the plurality of seal portions 62 a. Asshown in FIG. 8, the making of holes in the seal portions 62 a isperformed by moving the first hole-making member 41 downward to insertthe needles 41 b into the seal portions 62 a and then moving the firsthole-making member 41 upward to remove the needles 41 b from the sealportions 62 a. By this operation, holes are made simultaneously withrespect to the plurality of seal portions 62 a. The upward and downwardmovement of the first hole-making member 41 may be performedautomatically in the analytical apparatus X by the user's operation ofan operation switch, for example.

When the holes are made at the seal portions 62 a, the interior of theflow paths 51 are brought into communication with the outside throughthe first gas discharge ports 62 and the branching flow paths 53.Therefore, the sample liquid S retained in the liquid receiving portion50 moves through the flow paths 51 by capillary action. As indicated byarrows in FIG. 10A, when the sample liquid S reaches each channel 51A,the sample liquid S cannot move beyond the channel 51A to reach thereaction portion 51B and is guided to the branching flow path 53. As aresult, as schematically shown in FIG. 10B, the sample liquid S isretained in close proximity to the reaction portion 51B. Thus, thepreparation for the reaction of the sample liquid S with the reagent atthe reaction portion 51B is completed.

To guide the sample liquid s to the reaction portion 51B, a hole is madeat the seal portion 65 a. As shown in FIG. 9, the making of a hole atthe seal portion 65 a is performed by moving the second hole-makingmember 42 downward to insert the needle 42 a into the seal portion 65 aand then moving the second hole-making member 42 upward to remove theneedle 42 a from the seal portion 65 a. The upward and downward movementof the second hole-making member 42 may be performed automatically inthe analytical apparatus X by the user's operation of an operationswitch, for example.

When the hole is made at the seal portion 65 a, the interior of eachflow path 51 is brought into communication with the outside through thesecond gas discharge port 65 and the common flow path 64. Therefore, thesample liquid S, which has stopped upstream from the reaction portion51B, moves again through the flow path 51 by capillary action. Thus, asshown in FIG. 10C, the sample liquid S moves beyond the channel 51A ineach flow path 51, whereby the sample liquid S is supplied collectivelyto the plurality of reaction portions 51.

At each of the reaction portions 51B, the reagent portion 54 isdissolved by the sample liquid to establish a liquid phase reactionsystem. As the sample liquid S reacts with the reagent, the liquid phasereaction system exhibits a color depending on the amount of thesubstance to be detected in the sample or a reaction product is producedin accordance with the amount of the substance to be detected. As aresult, the liquid phase reaction system of the reaction portion 51Bexhibits light transmission characteristics (light absorptioncharacteristics) depending on the amount of the substance to bedetected. When a predetermined time period has elapsed from the samplesupply to the reaction portion 51B, the reaction portion 51B isirradiated with light from the light source 2 shown in FIGS. 1 and 2,and the amount of transmitted light is measured at the light receivingportion 3. The light irradiation by the light source 2 and the lightreceiving at the light receiving portion 3 are performed with respect toeach of the reaction portions 51B of the flow paths 51 by turning themount portion 1 by a predetermined angle. In the analytical apparatus X,the analysis of the sample, e.g. the computation of the concentration ofa substance to be detected, is performed based on the amount of lightreceived at the light receiving portion 3.

In the above-described analysis method, after the sample liquid S isguided to a portion (each channel 51A) close to the reaction portion51B, the sample liquid S is supplied from the channel 51A to thereaction portion 51B by opening the seal portion 65 a. Thus, the sampleliquid S can be supplied to the reaction portions 51B of the pluralityof flow paths 51 just by opening a single gas discharge port. Therefore,the time taken from when the operation to supply the sample liquid S isperformed (the seal portion 65 a is opened) until when the sample liquidreaches the reaction portions 51B can be shortened. Accordingly,variation of the time taken from the sample supply starting operation tothe completion of the sample supply among the flow paths 51 and amongeach measurement (among analytical tools) can be reduced. Thus, thetiming at which the reaction starts at the reaction portions 51 can beproperly controlled by the operation of opening the seal portion 65 a.Particularly, in this embodiment, the sample liquid can be suppliedsimultaneously to the plurality of reaction portions 51B just by openinga single gas discharge port. Therefore, it is possible to make thereaction time uniform among the reaction portions 51B and among aplurality of microdevices Y, whereby the measurement error can bereduced.

The present invention is not limited to the foregoing embodiments andmay be modified in various ways. For example, the present invention isapplicable to such a microdevice as shown in FIGS. 11 and 12, whichincludes a plurality of sample introduction ports. The microdevice Y′shown in the figures includes a substrate 5′, and a cover 6′ bonded tothe substrate via an adhesive sheet 7′. The substrate 5′ includes asample flow path 51 a′ and a reagent flow path 51 b′ respectivelyprovided with liquid receiving portions 50A and 50B at the ends thereof,and a reaction portion 51B′ for causing reaction between the sampleliquid and the reagent liquid. The cover 6′ includes a sampleintroduction port 61A and a reagent introduction port 61B. The adhesivesheet 7′ includes an opening 70′ formed to expose the two liquidreceiving portions 50A and 50B. In the opening 70′ is fitted aseparation film 8′.

In the analytical tool Y′, the sample liquid and the reagent liquidrespectively supplied through the sample introduction port 61A and thereagent introduction port 61B move in the thickness direction of theseparation film 8′ to reach the liquid receiving portions 50A and 60B.Thereafter, the sample liquid and the reagent liquid move to thereaction portion 51B′ by capillary action and undergo reaction at thereaction portion 51B′. The reaction product is analyzed by an opticalmethod.

In the analytical tool Y′ shown in FIGS. 11 and 12, the separation film8′ is arranged to collectively cover the two liquid receiving portions50A and 50B. However, a separation film may be arranged for each of theliquid receiving portions 50A and 50B.

Although the analysis based on the light which is transmitted when thereaction portion is irradiated with light is described in the foregoingembodiments, the present invention is also applicable to the sampleanalysis based on the light reflected from the reaction portion. Theirradiation of the reaction portion and the measurement of thetransmitted light need not necessarily be performed individually withrespect to each reaction portion but may be performed collectively withrespect to the plurality of reaction portions.

The present invention is applicable to an analytical tool which isdesigned to move a mobile component by capillary action. Therefore, theinvention is applicable to a tool for performing analysis by anelectrochemical method as well as that for performing analysis by anoptical method. Moreover, the invention is applicable not only to ananalysis method in which a sample is moved but also to an analysismethod in which a reagent is moved instead of a sample and a method inwhich a sample and a reagent are moved together with a carrier liquid.The application of the present invention is not limited to microdevices,and the invention is also applicable to other types of analytical tools.

1. An analytical tool comprising a liquid introduction port, one or aplurality of flow paths for moving a sample liquid introduced throughthe liquid introduction port, and a separation film for filtering thesample liquid supplied to the liquid introduction port and thenintroducing the sample liquid to said one or plurality of flow paths;wherein the sample liquid is caused to move through the separation filmin a thickness direction of the separation film for filtration.
 2. Theanalytical tool according to claim 1, wherein the flow path isstructured to move the sample liquid by capillary action.
 3. Theanalytical tool according to claim 1, wherein the sample liquidcomprises blood, and wherein the separation film separates blood cellsfrom the blood.
 4. The analytical tool according to claim 3, wherein theseparation film comprises a porous film having a minimum pore size of0.1˜3.0 μm.
 5. The analytical tool according to claim 1, wherein theseparation film is positioned higher than the flow path.
 6. Theanalytical tool according to claim 5, further comprising a liquidreceiving portion for retaining the sample liquid passed through theseparation film, the liquid receiving portion communicating with theliquid introduction port and the flow path, and wherein the separationfilm is spaced from a bottom surface of the liquid receiving portion. 7.The analytical tool according to claim 6, further comprising: asubstrate in which the liquid receiving portion is formed; a cover inwhich the liquid introduction port is formed; and an adhesive layerinterposed between the substrate and the cover, the adhesive layerincluding a through-hole for fitting the separation film.
 8. Theanalytical tool according to claim 6, wherein the plurality of flowpaths extend radially from the liquid receiving portion.
 9. Theanalytical tool according to claim 1, wherein at least two of theplurality of flow paths are respectively provided with reagent portionsfor reaction with the sample liquid, each of the reagent portions ofsaid at least two flow paths containing a different reagent; and whereinthe tool is adapted to measure a plurality of items from a single kindof sample liquid.
 10. The analytical tool according to claim 9, whereinthe reagent portions of said at least two flow paths are arranged on acommon circle.
 11. The analytical tool according to claim 9, whereineach of said at least two flow paths is structured to temporarily retainthe sample liquid upstream from the reagent portion before the sampleliquid is introduced to the reagent portion.
 12. The analytical toolaccording to claim 11, further comprising a branching flow path branchedfrom a channel set of the flow path; wherein the sample liquid istemporarily retained at the channel of the flow path by bringing thebranching flow path into communication with outside through a portionother than the liquid introduction port, and the sample liquid is causedto move through the flow path beyond the channel by bringing the flowpath into communication with outside through a portion other than theliquid introduction port.
 13. The analytical tool according to claim 12,wherein the flow path is connected to a gas discharge port fordischarging gas from the flow path, and the sample liquid is caused tomove beyond the channel by opening the gas discharge port.
 14. Theanalytical tool according to claim 1, wherein the flow path has aprincipal, rectangular cross section which has a width of 10 to 500 μmand a depth of 5 to 500 μm and which satisfies depth/width 0.5.
 15. Theanalytical tool according to claim 1, wherein the flow path includes ahydrophilically-treated inner surface.
 16. The analytical tool accordingto claim 15, wherein the inner surface of the flow path is so treatedthat a contact angle of pure water at the inner surface becomes 0˜80degrees.